Testing the occurrence of convergence in the cranio-mandibular shape evolution of living carnivorans

Convergence consists in the independent evolution of similar traits in distantly related species. The mammalian cranio-mandibular complex constitutes an ideal biological structure to investigate ecomorphological dynamics and the carnivorans, due to their phenotypic variability and ecological flexibility, offer an interesting case-study to explore the occurrence of convergent evolution. Here, we applied multiple pattern-based metrics to test the occurrence of convergence in the cranio-mandibular shape of extant carnivorans. To this aim, we tested for convergence in many dietary groups and analysed several cases of carnivoran convergence concerning either ecologically equivalent species or ecologically similar species of different body sizes described in the literature. Our results validate the occurrence of convergence in ecologically equivalent species in a few cases (as well as in the case of giant and red pandas), but almost never support the occurrence of convergent evolution in dietary categories of living carnivorans. Therefore, convergent evolution in this clade appears to be a rare phenomenon. This is probably the consequence of a complex interplay of one-to-many, many-to-one, and many-to-many relationships taking place between ecology, biomechanics and morphology.